Mask to mask resuscitator



May 19, 1959 E. SOVINSKY ET AL 2,887,104

MASK T0 MASK RESUSCITATOR Filed March 12, 1958 INVEIQTORS EugeneSavinsky Allan I. as!

1 r a) z E E 2 ATTORNEY United States Patent MASK 'ro MASK RESUSCITATOREuge'neSovinsky, Baltimore, and Allan L. West,"Bel Air,

Md., assignors to the United States of America as rep- This inventionherein described may be manufactured and used by or for the Governmentof the United States of America for governmental purposes without thepaymentto us of any royalty thereon.

This invention relates to a resuscitator particularly adapted for use ina contaminated atmosphere; It constitutes an improvement on thatdescribed and claimed in application Serial No. 721,073 filed March '12,1958 by Elwyn S. Brown et al. for. Mask-.to-Mask Resuscitator.

In the treatment of victims of poison gases, particularly the so-callednerve gases, it is frequently necessary to resort to some type ofartificial respiration or resuscitation. Since the resuscitation mustbe, carried out promptly, the method must be such that it can be carriedout in a contaminated atmosphere while both the casualty and theoperator are protected. The apparatus employed should be light, simple,and easily transported.

One previously known method is termed mouth-tomouth resuscitation. Itconsists in the operator blowing exhaled air into the mouth of thecasualty. Our apparatus makes possible a variation of this method, whichweterm fmask-to-mask resuscitation. The operator in- ;hales through acanister and gas mask. He then exhales into the lungs of the patient.

Finally, the patient exhales to the atmosphere. Our apparatus makespossible for the operator to carry out this cycle for extended periodsof time and insure that the casualty receives air of adequate oxygencontent. In common with the apparatus of the Brown et a1. application,our arrangement provides for re-breathing by the operator of part of hisexhaled air to maintain the carbon dioxide concentration in his lungssufliciently high to prevent difficulty due to hyperventilation.

Our apparatus includes refinements which render it more efiective inactual use in the field than shown in the Brown et al. applicationreferred to above.

In the drawings:

Figure 1 is a side elevation of the apparatus as a whole.

Figure 2 is a perspective view from the inside showing the mouthpiece inrelation to the nosecup of the operators mask.

Figure 3 is a sectional view taken on line 3-3 of Figure 2.

Figure 4 is an enlarged section on line 44, Fig. 1, showing the valvestructure.

Our resuscitator comprises essentially an operators gas mask 1 having acanister 3, a casualtys oronasal mask 5, a three-way valve 7 and aseparate canister 9. Flexible tubes 11 and 13 connect valve 7 to mask 1and canister 9, respectively. A flexible hood 15, preferably oftransparent plastic, covers the head and neck of the casualty and theoutlet ports of valve 7.

The operators mask 1 is a conventional gas mask from which the usualoutlet valve has been removed. It includes facepiece 17 and canister 3,having inlet opening 19. Within facepiece 17 is the conventional nosecup'ice . 2 21, which is provided with inlet valves 23 and whichcommunicates with outlet tube 25. I One of the important features of ourdevice is the mouthpiece 27. This mouthpiece includes a .stitfenedtubular shank 29 and aflexible rubber hollow body 31 having. a blowingopening 33. The mouthpiece body 31 is provided with an air inlet valvewhich comprises, a thin rubber disk 35 held in place by a resilientrubber plug 37 and covering perforations 39. Associated with canister 3is a conventional one-way inlet valve (not shown) which is mounted onthe facepiece 17. t p

Oronasal mask 5 is formed of rigid material, preferably a transparentplastic and carries on its lower edge an inflatable flexible rubber tube41 to insure a good seal with the face of the patient. Hood 15 isprovided with a drawstring 43 which is drawnabout the neck of thecasualty.

The valve 7 is shown in detail in Fig. 4. It includes an outer housing45 having a Y-connection 47. The two free ends of the Y are connected toflexible tubes 11 and 13. 1

The lower end of housing 45 is covered by a cap 49 which is pierced byair outlet perforations 51.

An inner housing formed of an outer ring 53 and an inner ring 55 isjoined to outer housing 45 by threads 57. These rings are joined by aflange pierced by outlet openings 59. Outer ring 53 terminates at itslower end in an outer valve seat 61 while inner ring 55 terminates atits upper end in inner valve seat 63. Inner ring 55 terminates at itslower end in shank 65 which is tightly joined to oronasal mask 5.

An outer valve is mounted on inner ring 55 and engages outer valve seat61, thus covering airoutlet open ings 59. The outer valve is formed of aheavy elastic rubber ring 67 which embraces inner ring 55 and, integraltherewith, a, thin resilient rubber valve disk- 69 which engages outervalve seat 61. 7

Within housing 45 is an inner valve. This valvecomprises a valve disk 71of thin, resilient rubber clamped at its periphery between outer housing45 and outer ring 53, and, integral therewith, a thickened centralportion 73 pierced by holes 75. Inner valve disk 71 engages inner valveseat 63, while the thickened central portion 73 forms a central valveseat.

A central valve is carried on the under side of thickened centralportion 73. It comprises a resilient rubber plug 77 which fits tightlyin an opening in thickened central portion 73 and an integral resilientvalve disk 79 which engages the central valve seat and covers holes 75.

Operation The casualty is placed on his back and his mouth is held openby any suitable means. A throat tube may be inserted to insure patency.Hood 15 is placed over his head and drawstring 43 is drawn about theneck to about the same tightness as a necktie. The operator then placesoronasal mask 5 over the mouth and nose of the casualty. The followingcycle of steps then begins.

a. The operator inhales through his mouth and nose. A negative pressureis created in mask 1, flexible tubes 11 and 13, Y-connection 45, andcanisters 3 and 9. The central valve disk 79 is held in the positionshown in Fig. 4, closing holes and preventing air flow into Y-connection 45 from oronasal mask 5 or the exterior. Air flows into themask 1 through canister 3 and also through canister 9, tube 13,Y-connection 45, flexible tube 11, outlet tube 25 and mouthpiece 27. Airfrom canister 3 enters nosecup 21 through inlet valves 23. If thepressure is less inside than outside of mouthpiece 27, air entersthrough perforations 39, preventing collapse.

b. The operator exhales by blowing into mouthpiece from theoperatorsface with resultant leakage.

27. Valve disk 35 closes perforations 3 in the mouthpiece. Themouthpiece is distended, forming a tight-seal against the operatorslips. Inner valve disk 71 seats on inner valve seat 63 and central valvedisk 79 is forced away from its seat, opening holes 75. Air then flowsinto oronasal mask 5 and thence to the' casualtys lung's, distendingthem.

At the beginning of step (b) the entire system is filled with freshpurified air. That in tube 11 is first'forced into the casualtys lungs,followed by the operators exhaled air. I

I c. The operator stops exhaling and the casualty exhales due to theelasticity of the lungs. Centralvalve disk 79 closes while inner valvedisk 71 and outer valve disk 69 are moved away from their valve seats 63and 61, respectively, allowing the casualtys exhaled air to enter hood'15, where it creates a slight 'sup'eratmospheric pressure "andeventually escapes around the casualtys neck. Step (6) may occursimultaneously with step (a) of the next cycle. At the end of step (b)tubes 11 and 13 are filled with'the operators exhaled air. When step-((1) is repeated, this exhaled air mingles with the freshair drawn inthrough canister 3. Breathing this mixture of exhaled and fresh airproduces a carbon dioxide concentration in the lungs sufficient toprevent excessive symptoms of hyperventilation, while the simultaneoususe of canisters 3 and 9 gives a lower breathing re'sist'ance'than wouldbe the case if all the-air were inhaled through canister 9 Moreover,mask 1 is constructed in such a manner that air drawn in thru canister 3flows overthe inner surfaces of the eyepieces, preventing fog'ging. Theresistance to flow of canister 3 is adjusted, e.g., by inser- -tion ofapertured plugs or disks in inlet opening 19, to

'secu're the' desired distribution of flow between canisters Sand 9. Themajor flow should be through canister 9.

The mouthpiece 27 has been found to be a highly deand the attempt to doso may cause separation of the mask The hollow form of the mouthpiece ishighly desirable'si'nce internal pressure causes it 'to seat tightlyagainst the operators lips.

The hood 15 adds to the protection of the casualty. Since a slightsuperatmospheric pressure of uncontaminated air is maintained, thepossibility of leakage of contaminated air into oronasal mask 5 isgreatly lessened.

Due to the provision of tube 13, the canister 9 may be positioned in anyconvenient location. For example, it can be attached to the operatorsbelt.

While we have described oneembodiment of our invention in detail, itwill be obvious that various changes are possible. We therefore'wish ourinvention to be limited solely by the scope of the appended claims.

We claim: p I

1. A mask-to-mask resuscitator comprising: an'operators mask, said maskcomprising a facepiece, an air purifying canister on said facepiece, anoutlet tube on said facepiece, and a mouthpiece saidfacepiece in cemmunication with said outlet tube, said mouthpiece being so constructedand positioned as to press against the lips 'of'the wearer of said mask;an oronasal casualtys a valve mounted on said casualtys mask, a flexibletube "connecting said outlet tube and said valveysaid valve being soconstructed as to admit -ai r fromsaid flexibl e tube to' said oronasalmask when the pressure is higher in said flexible tube than in saidoronasal n'iaskandfto discharge air from saidoronasal mask tothefexterio'r when the pressure 'is higher in said'or'onasal mask thanin said flexible'tube; and asecond canisterin communication with saidflexible tube adjacent said valve. ZQA "re'suscitator as defined inclaim 1" and further comprising a hood covering said valve andadapted tosurround the head and neck of the. casualty. I

v 13. A resuscitator as defined in claim 1, wherein "said mouthpiececomprises a hollow body of resilient material having a blowing openingin positionto engage thelips "offthe' wearer and a one-way valve soconstructedas to admit air to the interior of said hollow body.

References Cited in the file of this patent UNITED STATES PATENTS

